Painting the first coat video
Sanding after the first coat video
Paint the ceilings
Finish the floors:
   Clear Finish
   Faux-wood on MDF video
   Applied flooring
Clean the grooves and edges

Q: The instruction manual it recommends painting everything one coat now of interior semi gloss latex paint. 
Is that paint bought at the hardware store, how many colors are recommend, and how much paint is typically used for the whole project?

A: My local Aubuchon’s hardware store has a Benjamin Moore paint department and they have full mixing and matching capacity.  I have also used the Behr paints from Home Depot with good results.

“Everything” means everything that will be painted in the finished dollhouse.  Don’t paint the outsides of the roofs, the underside of the Base, or the insides of the foundations, for instance.

To get semigloss in a mixed color often means a minimum of one quart, which isn’t wasted on the main color of the outside or for white as a first-coat inside and a second coat for ceilings and trim (if chosen), although a pint will be enough if the white you are using inside isn’t also the primary color outside.  Detail colors can often be mixed in ‘samplers’ (7 or 8 oz) but the base for the ‘samplers’ is more often eggshell or satin, and I do not recommend that for large areas as it is harder than semigloss to keep clean, but I do use it for details.

Q: Another question for you: what kind of paint should I use for the exterior of the house?

A: I use semigloss interior latex (acrylic) everywhere I can on a dollhouse. Semigloss is the 'sweet spot' between the washability of high gloss and the appearance of flat, with high-gloss being tough and easy to clean but the 'glint' looks bad, and flat paint being forgiving in appearance but less durable and harder to keep clean. Semigloss is tough and can be gently cleaned without the glint of high gloss, so it looks good and stays looking good down the road.
The downside of semigloss is that most paint stores won't mix a custom color in less than quart quantities. I don't mind buying one quart of my choice of colors for the house... most houses use up a little over half of the quart particularly in the lighter colors, so it's the right quantity for choice and economy. But a house with several custom colors becomes expensive. So I choose 'samplers' for detail colors that won't be held to the needs of durability to such a degree. Samplers are typically 6 or 7 oz jars for testing a color in your home, and they can be mixed in whatever color you want but they are in a semi-flat base (satin or eggshell)... not what you would want for the broad walls, but just fine for a detail on a window or a bracket.

Q: I’ve started painting and construction:
Where two foundation pieces are eventually glued together (i.e., one side of conservatory foundation joins base house foundation), it is better to leave the faces of those two foundation pieces unpainted or do you recommend one base coat + sanding to soak into the wood even though it will not be visible when the project is complete.
Roof pieces that will ultimately have shingles applied - do you recommend one base coat + sanding before applying shingles?

A: I don’t paint parts that are completely and predictably unpainted in the final house, not even the ‘first coat and sanded’ step.  So I don’t paint the outside of the roof, the foundations, the underside of the Base Floor. There’s often a ‘pre-assembly’ group of parts before painting like the foundation and the stairs, but other things benefit from the sanding step after the first coat just because it is so much easier when parts are unassembled like the chimney or front steps (for houses with stacked steps for taller foundations). 

But the underside of the base floor or the shingling surface of the roofs does not a benefit in any way and, without the sanding step going all the way to the wood, it can, to some degree, interfere with gluing; besides it’s just more work.

Q: Walls:  I’m thinking:  leave all interior walls unpainted on the basis that most if not all rooms will have some decorative covering over the walls. 
Ceilings:  Here I’m inclined to paint the ceilings (the underside of the floors) before construction as if all ceilings will ultimately be painted.  In the event [the decorator] later decides to use a ‘faux tin ceiling’ in a room or two, it seems that dealing with sanding one or two painted ceilings afterwards would be more practical than trying to paint all the ceilings after construction.

A: For most houses I paint the interior parts one coat and sand them down to the wood before construction, and then do the second coat for whatever is painted after construction.  The thing that is slow in painting anything is the sanding. Sanding is always hardest on an assembled set of parts and is always easier for unassembled parts – enough easier to more than pay for whatever painting and sanding may have been unnecessary.  The wallpaper pastes I use adhere just fine to a painted-and-sanded surface and may even be easier to slide into position than on thirsty raw wood. 

Any time I am fine-tuning the interior spaces for furniture or furnishings (like a kitchen, for instance), I like to lay out the major pieces to make sure spaces fit.  Then I can place the walls perfectly for what they are holding, a counter and refrigerator, a bed and end table, a sofa set that locates a wall – all the containers fine-tuned for what they contain.  If the interior spaces are left undefined until that can take place I know the interior wall  placement will be optimized for my ideal plan, and the gods of interior decorating will be smiling on me.  I know the glue for the Dividers will stick to a ‘sanded-down-to-wood’ surface, and the joint will be further reinforced by the paint when the second-coat is applied.

Q (JM4600, JM1065): I have a question regarding painting of the floor and ceiling.

I see in the instructions that glue won't stick to paint but am wondering if glue will stick to the first coat that is sanded to the wood. I ask this because dividers and the front walls get glued to both the ceiling and floors. Wondering if I should attach first and paint later although the instructions and videos mention painting first.

A: It's the sanding after the first coat that guides the decision to paint-and-sand first... sanding is much, much easier with the parts laid out and flat, and the quality of the paint job is all about the quality of the sanding, so painting-and-sanding first is persuasive in order to get the best possible sanding job!! One-coat-and-sanded-down-to-the-wood will accept glue, and that is what I do. 

I paint anything that should be painted one-coat and then sand down to the wood. I second-coat the outsides of anything with a clapboard profile, as well as the porch and balcony floors/ceilings before or during assembly. I don't second-coat anything on the inside before assembly, except that I second-coat (or wallpaper) the walls inside the Tower (JM4600) before I add the next level so I can work thru the open ceiling.  I always get at least one of the sequences wrong, but that's more-or-less what I aim for.